PaperUI: Resizing the browser window makes the menu disappear too quickly

[triller-telekom]

If I resize my browser with PaperUI open the left menu disappears once the browser reaches a certain width.

On my screen this happens at about 60% of my screensize which is 1920x1080. I think it would be sufficient if the menu disappears once the width is only about 1/3 of my screenwidth, so lets say ca 350px.

[htreu]

This one should wait until #3782 is merged: The structure of lists changed there heavily and the fix for this issue needs some of the changes.